Invisible-type slide fastener

ABSTRACT

Invisible-type fastener is made from ladder-type strip. Projections on edge of each fastening element are engaged by attaching thread to hold each element against lateral slippage with respect to tape.

1451 Oct. 10, 1972 United States Patent Jones [56] References Cited UNITED STATES PATENTS [54] INVISIBLE-TYPE SLIDE FASTENER [72] Inventor:

Cuckson.............24/205.13 D 1/1970 Waldes .......,.24/205 13 R Primary Examiner-Bernard A. Gelak Attorney-Dallett Hoopes [22] Filed:

[21] Appl.No.: 145,251

ABSTRACT Invisible-type fastener is made from ladder-type strip.

[52] US. Cl...... ........24/205.1, 24/205.13 .A44b 19/34, A44b 19/02 581 Field of Search ....24/205.13 D, 205.1 c, 205.13 Projections on edge of each fastening element are gaged by attaching thread to hold each element against lateral slippage with respect to tape.

6 Claim, 8 Drawing Figures INVISIBLE-TYPE SLIDE FASTENER This invention relates to an invisible-type slide fastener. More specifically, this invention relates to an invisible-type slide fastener comprised of a strip of interconnected fastening elements as generally described in U.S. Pat. 3,414,948 issued Dec. I0, 1968.

In the prior art, a number of invisible-type slide fasteners are disclosed. Generally, this genus comprises in each stringer a longitudinally folded tape forming a U in cross section to which a row of fastening elements is secured, with the heads of the elements aligned generally adjacent the fold line. When the fastening elements of two such stringers are interconnected to form a chain, the appearance of the interengaged fastener from the tape side is a single inconspicuous line having the appearance of a seam with no fastening elements visible, hence, the term invisible fastener.

One problem with prior devices of this type, especially the plastic fastener element type, is that when placed under stress due to a pulling force transverse of the fastener, the fastening elements tend to move laterally with respect to the tape so that the heads or teeth of the element are exposed from the tape side to give what is aptly termed in the trade a grin. Many attempts have been made to avoid this effect, usually by placing a groove or bump in the fastener element adjacent where the element is engaged by stitching. Prior attempts have not been particularly satisfactory.

Another criticism of plastic invisible-type fasteners in the prior art is that they have been relatively inflexible. One reason for this is that a heavy cord has often been used inside the row of elements as an anchor for the attaching stitches.

The present invention has for its object to avoid the criticism which devices of the prior art have deserved. By placing special notches and projections on the individual fastener elements closely adjacent the tape and engaging the notches and projections with the line of stitching, the present invention avoids the lateral slipping and grinning which has been invariably present in prior devices. No anchoring cord is necessary. Moreover, making the notches and projections of adjacent elements interfit, the present invention provides an extremely flexible slide fastener.

In addition, devices embodying the present invention are simpler and more economical to produce than prior devices in that in the present device only one line of stitching is necessary whereas a plurality of lines are used in prior devices.

FURTHER OBJECTS AND FEATURES OF THE INVENTION WILL BE APPARENT FROM THE FOLLOWING SPECIFICATION INCLUDING THE DRAWINGS WHEREIN:

FIG. 1 shows a strip of interconnected fastener elements useful in the present invention;

FIG. 2 is an end view of an element shown in FIG. 1;

FIG. 3 is an end view of a fastener element in accordance with the invention after having been folded to form a U shape in cross section;

FIG. 4 is a top plan view of an individual fastener element;

FIG. 5 is a perspective view, partly in section, showing a stringer embodying the invention;

FIG. 6 is a transverse sectional view showing a chain comprising a pair of interrneshing stringers embodying the invention;

FIG. 7 is a top plan view of a chain embodying the invention; and

FIG. 8 is a transverse sectional view of a stringer having a modified form of fastener element and embodying the invention.

Briefly, the invention is a stringer for an invisibletype slide fastener, the fastening elements being of U shape to comprise a central base, an inside limb and an outside limb, the elements being interconnected by continuous cords at the distal ends of each limb. The inside limb is formed with substantially aligned projectionsand notches on opposite transverse edges, and a line of stitching engaging the projections connects the strip to the tape with the base of the fastener elements adjacent the fold line of the tape.

Referring more specifically to the drawings, a laddertype strip of interconnected plastic fastener elements is generally designated 10 in FIG. 1. It comprises a series of fastener elements 12 each fonned with a central head 14 and relatively flat limbs 16 and 18 extending outward therefrom. The distal ends of the limbs are connected by relatively continuous cords 20 and 22 about which the elements 12 are molded.

In the manufacture of the stringers in accordance with the invention, the individual fastener elements are folded into U shape as shown in FIG. 3 to present the limbs 16 and 18 now adjacent each other and the base 24'which includes the head 14 and a cavity 26, the heads and cavities of adjacent elements being adapted to intermesh with comparable parts on a cooperant stringer. As shown in FIG. 1, thelimbs 16 are each formed with substantially aligned V-shaped projections 28 and notches 30 arranged so that when a stringer is flexed longitudinally, the notch on one element will receive the projection on the next and so on. Additionally, as shown, the projection may be somewhat smaller than the notch to allow room for stitching as will be apparent.

FIG. 5 shows the strip of connected fastener elements 12 attached to a tape 32. As shown, the tape is folded longitudinally to show a U-shaped cross section comprising two legs 34 and 36 and a connecting bight 38. As shown, the strip 10 is attached tothe tape with the limbs 16 on one side of the elements against a leg 34 and the row of bases 24 adjacent the bight 38.

As shown, a strip 10 of fastener elements is attached to the tape 32 by means of a line of stitching 40. The line of stitching tightly engages each fastener element and engages the element adjacent the projection 28 on each element, being disposed between that projection and the base 24. In addition, the stitching (the looper thread as shown) engages the outer surface of the limb 18 (FIG. 6) in a groove 42 which protects the stitching against wear and serves to resist lateral movement of the fastener element with respect to the tape. The majority of such resistance, however, comes with the engagement of the stitching 40 with the projections 28 as will be clear from FIG. 6.

Apparent from FIG. 7 is the accommodation by the notches 30 on successive fastener elements of the projections 28 with suitable room to avoid interference of the stitching with such accommodation.

While the present chain is depicted as having the strip of fastener elements sewn to the tape, a warp thread of the tape may actually weave the elements thereinto. It will be seen, incidentally, that the threads used to attach the elements to the tape may be disposed close to, but not over, the cavity 26 to avoid interference with the action of the zipper.

An additional lateral stability of the fastening elements with respect to the tape is achieved in modification as shown in FIG. 8 wherein the inside limb 16 of the fastener element is formed with a rib 50 disposed longitudinally of the strip of fastener elements and defining therealong a shoulder or ledge 52 against which abuts the edge 54 of the tape leg 34'. Additionally, the rib gives strength to the heel of the element .where the element is engaged by the slider and the rib keeps the edge of the tape from curling away from the element due to slider action. This version, of course, includes the projection 28'.

In the versions shown, the projection 28 (FIG. 7, for example) extends out toward the adjacent element beyond an imaginary centerline (shown dotted) disposed halfway between the two fastening elements and extending parallel to them. In this disclosure, and in the claims hereafter, the term tape is used to indicate the fabric to which the strip of fastener elements is secured. It should be understood, however, that in some cases it may be desirable to secure the line of fastener elements directly to a panel of the garment or article itself. Hence, the term tape is intended to be interpreted as including such a panel or other fabric bordering the opening.

In all versions shown, the fastener of the invention provides a resistance to lateral displacement and a flexibility which is remarkable and superior to prior invisible fasteners. Because of this stability, it is only necessary to use one line of stitching in securing the strip of fastener elements 'to the tape.

Other variations of structure are possible under the invention within the following claim language:

I claim:

1. A stringer for an invisible-type slide fastener comprising:

a. a strip of connected U-shaped plastic fastening elements each comprising a pair of relatively flat superposed limbs and a base, the base being formed with a head and cavity adapted to matingly engage the base of similar elements on a cooperant stringer, the limbs on one side of the strip each being formed with a V-shaped notch on one transverse edge and a substantially aligned V-shaped projection on the opposite transverse edge, the notch adapted to accommodate the projection on tively by a pair of continuous cords;

b. a 'woven tape folded longitudinally to form a U- thread me s passing aroun each fastening element and isposed between e pro ection and the head whereby the projection limits the lateral movement of the fastener elements on the tape.

2. A stringer as described in claim 1 wherein the outer surfaces of the elements on the limb on said other side of the stringer are each formed with a groove extending longitudinally of the strip, the groove receiving the thread means to protect it against wear.

3. A chain as described in claim 1 wherein the inner surface of said limbs on said one side of the stringer are formed adjacent their distal ends with a rib defining a shoulder receiving the proximate edge of the tape in abutting relation.

4. A chain as described in claim 1 wherein the thread means is a line of stitching.

5. A stringer for an invisible-type slide fastener comprising:

a. a strip of connected U-shaped plastic fastening elements each comprising a pair of relatively flat superposed limbs and a base, the base being formed with means adapted to matingly engage the base of similar elements on a cooperant stringer, the limbs being formed with a recess on one transverse edge and a substantially aligned projection on the opposite transverse edge, the recess adapted to accommodate the projection on the adjacent element, the U-shaped elements being connected at the ends of their limbs respectively by a pair of continuous cords;

b. a woven tape folded longitudinally to form a U- shape in transverse cross section with two legs and a connecting bight, the strip being positioned on the tape against one leg of the tape and the bases of the fastening elements being adjacent the bight; and

c. thread means securing the strip to the tape, the

thread means passing around each fastening element and disposed between the projection and the head whereby the projection limits the lateral movement of the strip on the tape.

6. A stringer as described in claim 5 wherein the projection extends out from the fastening element toward such adjacent element beyond a centerline disposed halfway between the two fastening elements and exthe adjacent element, the U-shaped elements tending parallel) thembeing connected at the end of their limbs respec l I i t 

1. A stringer for an invisible-type slide fastener comprising: a. a strip of connected U-shaped plastic fastening elements each comprising a pair of relatively flat superposed limbs and a base, the base being formed with a head and cavity adapted to matingly engage the base of similar elements on a cooperant stringer, the limbs on one side of the strip each being formed with a V-shaped notch on one transverse edge and a substantially aligned V-shaped projection on the opposite transverse edge, the notch adapted to accommodate the projection on the adjacent element, the U-shaped elements being connected at the end of their limbs respectively by a pair of continuous cords; b. a woven tape folded longitudinally to form a U-shape in transverse cross section with two legs and a connecting bight, the strip being positioned on the tape with the limbs on the said one side of the strip being disposed against one leg of the tape and the bases of the fastening elements being adjacent the bight; and c. thread means securing the strip to the tape, the thread means passing around each fastening element and disposed between the projection and the head whereby the projection limits the lateral movement of the fastener elements on the tape.
 2. A stringer as described in claim 1 wherein the outer surfaces of the elements on the limb on said other side of the stringer are each formed with a groove extending longitudinally of the strip, the groove receiving the thread means to protect it against wear.
 3. A chain as described in claim 1 wherein the inner surface of said limbs on said one side of the stringer are formed adjacent their distal ends with a rib defining a shoulder receiving the proximate edge of the tape in abutting relation.
 4. A chain as described in claim 1 wherein the thread means is a line of stitching.
 5. A stringer for an invisible-type slide fastener comprising: a. a strip of connected U-shaped plastic fastening elements each comprising a pair of relatively flat superposed limbs and a base, the base being formed with means adapted to matingly engage the base of similar elements on a cooperant stringer, the limbs being formed with a recess on one transverse edge and a substantially aligned projection on the opposite transverse edge, the recess adapted to accommodate the projection on the adjacent element, the U-shaped elements being connected at the ends of their limbs respectively by a pair of continuous cords; b. a woven tape folded longitudinally to form a U-shape in transverse cross section with two legs and a connecting bight, the strip being positioned on the tape against one leg of the tape and the bases of the fastening elements beinG adjacent the bight; and c. thread means securing the strip to the tape, the thread means passing around each fastening element and disposed between the projection and the head whereby the projection limits the lateral movement of the strip on the tape.
 6. A stringer as described in claim 5 wherein the projection extends out from the fastening element toward such adjacent element beyond a centerline disposed halfway between the two fastening elements and extending parallel to them. 